Automatic starting mechanism



Nov. 6, 1934. M NQ 1,979,920

AUTOMATIC STARTING I JECHANISM Filed Feb. 24, 1931 19 a llll' 5:3 5 a Ai 18 C) 22 10 E 45 4 AIM .ALA

mummy LA A INVENTOR BY MauPl'ce l? Whz'iney A T TORNE Y Patented Nov. 6,1934 UNITED STATES PATENT OFFICE Eclipse Machine Company,

poration of New York Application February 24,

4 Claims.

This invention relates to automatic starting mechanism for internalcombustion engines and more particularly to such a mechanism including adevice for cutting off the power from the starter in case said starteris subjected to sustained overload. Such a condition is sometimesbrought about by an attempt to start a motor vehicle with thetransmission gears engaged and the brakes set, or by abutting or jammingof the ends of the teeth of a starting pinion against the teeth of anengine gear. When an electrical starting motor is thus prevented fromrotating, the battery is subjected to a heavy current drain, and theenergy thereof is dissipated as heat within the starting motor and otherelements or the starting circuit.

It is an object of the present invention to provide an automaticelectrical starting mechanism embodying a novel device for opening themotor circuit in response to an overload, which device is simple andeconomical to construct and reliable in operation.

Another object of the invention is to provide such a device whichoperates automatically to open the starting circuit and hold saidcircuit open until reset by the operator.

A further object is to provide such a device in which the resetting isaccomplished by the operation 01' a manual switch such as the ignitionswitch of the engine, which is also arranged to control the operation ofthe automatic starting mechanism.

Further objects and advantages will be apparent to those skilled in thisart from the following description taken in connection with theaccompanying drawing in which the single figure is a semi-diagrammaticillustration of the preterred form of the invention, the automaticstarting switch being shown in elevation and partly in section.

In the drawing there isillustrated a starting circuit including abattery 10 having one terminal grounded at 11 and the opposite terminalconnected by a lead 12 to an automatic starting switch comprisingstationary elements 13 and 14 and a movable bridging element 16. Switchelement 14 is connected through a single turn coil 17 and lead 18 to aconductor 19 which in turn is connected by a lead 20 to a starting motorSM which is grounded at 21. The single turn coil 17 is provided with anadjustable magnetic core 22 which is surrounded by a spacing sleeve 23.

The movable starting switch element 16 is mounted on a magnetic switchplunger 24, suitably insulated therefrom, which plunger is nor- Elmira,N. Y., a cor- 1931, Serial No. 518,012

mally retained in its upper position as illustrated by suitable meanssuch as a spring 26. A solenoid 27 is arrangedto surround the lower endof switch plunger 24 and is adapted when energized to draw the plungerdown in order to close the starting switch.

Solenoid 27 forms one element of a control circuit for the startingswitch which includes a manual switch 28, which is preferably theignition switch of the engine and which is connected to the battery lead12, a lead 29, a heatresponsive element 30, normally closed contacts 31and 32, lead 33, lead 34, normally closed contacts 36 and 37, springstrip 38 and ground connection 39.

Contact 36 is stationary while contact 37 mounted on spring strip -38 isadapted to be moved out of engagement therewith by means of a lever 40pivoted at one end at 41 and having a roller 42 on its free end adaptedto engage a weight member 7 43 on the end of the spring strip 38 andbend said strip backward. Lever 40 is provided intermediate its lengthwith a pin 44 adapted to extend laterally between a pair of flanges 46and 47 on a magnetic relay plunger 48. The relay plunger is normallyheld in its upper position in contact with the spacing sleeve 23 bysuitable means such as a spring 49, so that the roller 42 is out ofengagement with the member 43 and contact 37 is therefore allowed toengage the fixed 86 contact 36. The lower end of relay plunger 48 issurrounded by a voltage coil 50 and a generator coil 51 which whenenergized attract the relay plunger downward. Voltage coil 50 isconnected to the starting switch element 14 by a lead 52, and isgrounded at its opposite terminal at 53. The generator coil 51 isconnected at one end to the generator G by a lead 54, the opposite endof said coil being grounded at 53.

The heat-responsive element 30 is in the form 01 a bi-metallic stripfixedly mounted at one end as by means of a bracket 56 and carrying themovable contact 31 on its free end. The bi-metallic element 30 is sopositioned that the contact 31 on the free end thereof is normally inengagement with the fixed contact 32 but an increase in temperature ofsaid element will cause the free end thereof to bend upwardly and movethe contact 31 out of such engagement.

Suitable heating means for the heat-responsive element 30 is providedsuch as a ribbon of resistance metal 57, wrapped around theheat-responsive element 30 and connected in shunt with the conductor 19as illustrated. It will be seen from this arrangement that the heatingelement 57 will be traversed by an aliquot portion of the total currenttraversing the starting circuit and the heating eflect thereof on theelement 30 will therefore be proportional to the load on the startingcircuit. Since a predetermined rise in temperature of the element 30will cause the contact 31 to move out of engagement with contact 32, itis evident that this arrangement provides means for opening the controlcircuit and consequently breaking the starting circuit in response to apredetermined overload on the starting motor.

According to the present invention, means are provided for preventingthe return of the heatresponsive element 30 to its normal position atterit has been actuated to open the contacts 31, 32, until the operator hasreset the device for further automatic operation. As here illustrated,this means takes the form of a latch member 58 in the form of a bellcrank lever pivoted at 59 and having an arm 60 provided with a notch 61adapted to receive the end of the heat responsive element 30 when thearm 60 is pressed toward said element. In order to move the arm 60 intosuch engaging position, an arm 62 of the bell crank lever is providedwith a magnetic plunger 63 which is adapted to be actuated by a solenoid64. Solenoid 64 is connected at one end by a lead 66 to the lead 29 fromthe manual switch 28, and is grounded at its other end at 67. Means suchas a spring 68 is provided for yieldably urging the arm 60 in adirection to release the end of the heat-responsive member 30 when thesolenoid 64 is deenergized.

In operation, and starting with the parts in the position illustrated inthe drawing, closure of the manual switch 28 completes a circuit frombattery 10 through lead 12, switch 28, lead 29, bracket 56,heat-responsive element 30, contacts 31, 32, lead 33, switch coil 27,lead 34, contacts 36, 37, spring strip 38 and ground connection 39. Theconsequent energization of switch coil 2'7 draws the switch plunger 24downward causing the starting switch member 16 to close the startingcircuit whereupon the starting motor is energied to crank the engine. Atthis time the voltage coil 52 is energized by reason of its connectionto the starting switch member 14 but does not draw the relay plunger 48downward since the heavy starting current traversing the single turncoil 1'7 magnetizes the core 22 thereof sufficiently to retain the relayplunger in its upper position.

When the engine becomes self-operative, the relief of the load on thestarting motor causes a large reduction in the current traversing thestarting circuit, thus weakening the efiect of the single turn coil 1'7and strengthening the voltage coil 50 by reason of the increased voltagedrop therethrough so that said plunger is drawn downward causing theroller 42 to engage the weight member 43 and bend the spring strip 38backward, moving contact 37 out of engagement with contact 36. Thecontrol circuit is thus broken, deenergizing the switch coil 2'7 andallowing the spring 26 to open the starting switch. The volt-' age coil50 however, retains the plunger 48 in its lower position due to a slightamount of current generated by the starting motor spinning in itsresidual field. Before the starting motor slows down sufficiently todeenergize the voltage coil, the generator G which is driven from theengine picks up sufliciently to energize the generator coil 51 and thusretain the plunger 48 in its lower position.

If, during the starting operation, the engine should be prevented fromrotation as by being left in gear, or if the starting pinion shouldengage end to end with the engine gear, and become wedged therewith, aheavy current will be caused to traverse the starting circuit since thestarting motor is unable to rotate and generate any counterelectro-motive force. A proportional part or this heavy flow of currenttraverses the heating element 57, which accordingly raises thetemperature of the bi-metallic element 30, causing the same to bendupward and engage in the notch 61 of the lever arm 60 with the contactmember 31 out of engagement with contact 32. The control circuit is thusbroken and the starting switch'allowed to open.

Closure of the manual switch 28 completes an electrical circuit frombattery 10 through lead 12, switch 28, lead 29, lead 66 and solenoid 64to the ground at 67. The consequent energization of solenoid 64 causesthe arm 60 of latch 58 to be urged toward the heat-responsive element30. When, therefore, said member bends upwardly, the end thereof entersthe notch 61 in the arm 60, and is retained thereby as long as themanual switch 28 remains "closed. The starting mechanism is thus held ininoperative position until the operator has taken the necessary steps tofree the starting gearing and allow operation thereof.

In order to reset the device for further automatic operation, it is onlynecessary for the operator to open the manual switch 28 whereupon thesolenoid 64 is deenergized and the spring 68 retracts the arm 60,allowing the heat-responsive element 30 to escape from the notch 61 andclose the contacts 31, 32. Subsequent closure of the manual switch 28causes the automatic starting operation to be repeated.

Although but one form of the invention has been illustrated anddescribed in detail, it will be understood that various otherembodiments are possible and that various changes may be made in theproportions and arrangements of the parts without departing from thespirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. Automatic starting mechanism for internal combustion enginesincluding a starting motor circuit having an automatic starting switch,a control circuit for said starting switch having a manual switchtherein, means responsive to an overload on the starting circuit forbreaking said control circuit, and means controlled by said manualswitch for maintaining said break in the control circuit.

2. In an automatic starting mechanism for internal combustion engines, astarting circuit including an automatic starting switch, a controlcircuit for said starting switch including a pair of contacts, a memberadapted when heated to operate said contacts to cause the startingswitch to be opened, means for heating said member arranged to beenergized by current traversing the starting circuit, means forpreventing the return of the heat-responsive member to normal positionand manual means for releasing said preventing means.

3. In an automatic starting mechanism for internal combustion engines, astarting circuit including an automatic starting switch, a controlcircuit for said starting switch including a manual switch and a pair ofcontacts, a member adapted when heated to operate said contacts to causethe starting switch to be opened, means for heating said member arrangedto be energized by current traversing the starting circuit and means tocause the starting switch to be opened, means for heating said memberarranged to be energized by current traversing the starting circuit, alatch for holding said contacts open, said latch being biased toreleasing position, and electro-magnetic means under the control of saidmanual switch for moving said latch to operative position.

MAURICE P. WHITNEY.

